Publications (3)0 Total impact
ABSTRACT: The polymerase chain reaction (PCR) was used to study the prevalence of the macrolide resistance genes ermA , ermB , ermC , msrA/msrB , ereA and ereB , in 851 clinical isolates of Staphylococcus aureus and 75 clinical isolates of Enterococcus faecium that were erythromycin resistant. The isolates were from 24 European university hospitals. In S. aureus , the ermA gene was more common in methicillin-resistant S. aureus (MRSA) isolates (88%) than in methicillin-susceptible S. aureus (MSSA) isolates (38%), and occurred mainly in strains with constitutive MLS B expression. In contrast, ermC was more common in MSSA (47%) than in MRSA (5%), occurring mainly in strains with inducible expression. The ereB gene was only found in MRSA isolates expressing a constitutive MLS B phenotype (1%). The ereA gene was not detected. Macrolide resistance by efflux due to the msrA / msrB gene was only detected in MSSA isolates (13%). In contrast to S. aureus , erythromycin resistance in E. faecium was almost exclusively due to the presence of the ermB gene (93%).